Lab-grown diamonds are created using two primary methods: High Pressure High Temperature (HPHT) and Chemical Vapor Deposition (CVD). In HPHT, carbon is subjected to high pressure and temperature, mimicking natural diamond formation. CVD involves introducing a carbon-containing gas into a chamber, where it breaks down and deposits diamond material onto a substrate. These processes result in the growth of diamond crystals, which are then cut and polished into gem-quality stones. China makes most HPHT rough diamonds while India makes all or most CVD raw diamonds.CVD’s are mostly made in VS & VVS2 clarity. HPHT, China makes and dumps so price is good. HPHT at times can test as not a diamond (because it has some remnants of Nitrogen gas that doesn’t get extracted fully) while CVD will never test as anything but a diamond even by cheap diamond testers.